杂质(Co,Si,Ca,Cu,Ni)在磁铁矿中的类质同象研究现状

磁铁矿(Fe_3O_4)是具有反尖晶石结构的铁氧化物,理论上,在四面体位置上(A位)存在半数的Fe^(3+)和八面体位置上(B位)存在全部的Fe^(2+)和剩余半数的Fe^(3+)。因为其特殊的晶体结构以及其他阳离子(如Co^(2+),Ni^(2+),Ca^(2+),Si^(4+),Cu^(2+)等)类质同象的发育,会导致其晶胞参数、粒径、磁超精细场、位点数量、饱和磁矩、矫顽场等参数改变,并且这些阳离子在磁铁矿中的占位具有选择性。磁铁矿实验矿学对了解自然界矿物的生成条件及其有关理论提供了极大的帮助。

Magnetotelluric extremum boundary inversion based on different stabilizers and its application in a high radioactive waste repository site selection

Geophysical inversion under different stabilizers has different descriptions of the target body boundary,especially in complex geological structures.In this paper,we present an extremum boundary inversion algorithm based on different stabilizers for electrical interface recognition.Firstly,we use the smoothest and minimum-support stabilizing functional to study the applicability of adaptive regularization inversion algorithm.Then,an electrical interface recognition method based on different stabilizers is developed by introducing extremum boundary inversion algorithm.The testing shows that the adaptive regularization inversion method does work for different stabilizers and has a low dependence on the initial models.The ratio of the smooth and focusing upper and lower boundaries obtained using the extremum boundary inversion algorithm can clearly demarcate electrical interfaces.We apply the inversion algorithm to the magnetotelluric(MT)data collected from a preselected area of a high-level-waste clay-rock repository site in the Tamusu area.We recognized regional structures with smooth inversion and the local details with focusing inversion and determined the thickness of the target layer combined with the geological and drilling information,which meets the requirement for the site of the high-level waste clay-rock repository.